// observation.go presents observation payloads in metric and US shapes.
// Layer: adapters/inbound/httpapi/presenter observation payload mapping.
package presenter

import (
	"time"

	"gitea.maximumdirect.net/ejr/weatherfeeder/model"
)

// WeatherObservationUS is the US-customary response shape for observations.
type WeatherObservationUS struct {
	StationID               string                 `json:"stationId,omitempty" xml:"stationId,omitempty"`
	StationName             string                 `json:"stationName,omitempty" xml:"stationName,omitempty"`
	Timestamp               time.Time              `json:"timestamp" xml:"timestamp"`
	ConditionCode           model.WMOCode          `json:"conditionCode" xml:"conditionCode"`
	IsDay                   *bool                  `json:"isDay,omitempty" xml:"isDay,omitempty"`
	TextDescription         string                 `json:"textDescription,omitempty" xml:"textDescription,omitempty"`
	TemperatureF            *float64               `json:"temperatureF,omitempty" xml:"temperatureF,omitempty"`
	DewpointF               *float64               `json:"dewpointF,omitempty" xml:"dewpointF,omitempty"`
	WindDirectionDegrees    *float64               `json:"windDirectionDegrees,omitempty" xml:"windDirectionDegrees,omitempty"`
	WindSpeedMph            *float64               `json:"windSpeedMph,omitempty" xml:"windSpeedMph,omitempty"`
	WindGustMph             *float64               `json:"windGustMph,omitempty" xml:"windGustMph,omitempty"`
	BarometricPressureInHg  *float64               `json:"barometricPressureInHg,omitempty" xml:"barometricPressureInHg,omitempty"`
	VisibilityMiles         *float64               `json:"visibilityMiles,omitempty" xml:"visibilityMiles,omitempty"`
	RelativeHumidityPercent *float64               `json:"relativeHumidityPercent,omitempty" xml:"relativeHumidityPercent,omitempty"`
	ApparentTemperatureF    *float64               `json:"apparentTemperatureF,omitempty" xml:"apparentTemperatureF,omitempty"`
	PresentWeather          []model.PresentWeather `json:"presentWeather,omitempty" xml:"presentWeather,omitempty"`
}

func ObservationPayload(obs *model.WeatherObservation, units Units, precision int) any {
	if obs == nil {
		return nil
	}
	if units == UnitsUS {
		converted := WeatherObservationUS{
			StationID:               obs.StationID,
			StationName:             obs.StationName,
			Timestamp:               obs.Timestamp,
			ConditionCode:           obs.ConditionCode,
			IsDay:                   copyBoolPtr(obs.IsDay),
			TextDescription:         obs.TextDescription,
			TemperatureF:            roundedPtr(celsiusToFahrenheitPtr(obs.TemperatureC), precision),
			DewpointF:               roundedPtr(celsiusToFahrenheitPtr(obs.DewpointC), precision),
			WindDirectionDegrees:    roundedPtr(copyFloat64Ptr(obs.WindDirectionDegrees), precision),
			WindSpeedMph:            roundedPtr(scalePtr(obs.WindSpeedKmh, kmhToMphFactor), precision),
			WindGustMph:             roundedPtr(scalePtr(obs.WindGustKmh, kmhToMphFactor), precision),
			BarometricPressureInHg:  roundedPtr(scalePtr(obs.BarometricPressurePa, paToInHgFactor), precision),
			VisibilityMiles:         roundedPtr(scalePtr(obs.VisibilityMeters, metersToMilesFactor), precision),
			RelativeHumidityPercent: roundedPtr(copyFloat64Ptr(obs.RelativeHumidityPercent), precision),
			ApparentTemperatureF:    roundedPtr(celsiusToFahrenheitPtr(obs.ApparentTemperatureC), precision),
			PresentWeather:          append([]model.PresentWeather(nil), obs.PresentWeather...),
		}
		return converted
	}

	rounded := model.WeatherObservation{
		StationID:               obs.StationID,
		StationName:             obs.StationName,
		Timestamp:               obs.Timestamp,
		ConditionCode:           obs.ConditionCode,
		IsDay:                   copyBoolPtr(obs.IsDay),
		TextDescription:         obs.TextDescription,
		TemperatureC:            roundedPtr(copyFloat64Ptr(obs.TemperatureC), precision),
		DewpointC:               roundedPtr(copyFloat64Ptr(obs.DewpointC), precision),
		WindDirectionDegrees:    roundedPtr(copyFloat64Ptr(obs.WindDirectionDegrees), precision),
		WindSpeedKmh:            roundedPtr(copyFloat64Ptr(obs.WindSpeedKmh), precision),
		WindGustKmh:             roundedPtr(copyFloat64Ptr(obs.WindGustKmh), precision),
		BarometricPressurePa:    roundedPtr(copyFloat64Ptr(obs.BarometricPressurePa), precision),
		VisibilityMeters:        roundedPtr(copyFloat64Ptr(obs.VisibilityMeters), precision),
		RelativeHumidityPercent: roundedPtr(copyFloat64Ptr(obs.RelativeHumidityPercent), precision),
		ApparentTemperatureC:    roundedPtr(copyFloat64Ptr(obs.ApparentTemperatureC), precision),
		PresentWeather:          append([]model.PresentWeather(nil), obs.PresentWeather...),
	}
	return &rounded
}